ClinVar

Description

Variant summary: COL4A3 c.4825C>A alters a conserved nucleotide resulting in a synonymous change. 4/4 computational tools predict no significant impact on normal splicing. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 0.00018 in 249414 control chromosomes, predominantly within the Ashkenazi Jewish subpopulation at a frequency of 0.0034, within the gnomAD database. This frequency is approximately 2 fold of the maximum expected allele frequency for a pathogenic variant in COL4A3 causing autosomal recessive Alport Syndrome (0.0034 vs 0.0019), suggesting this may be a benign variant found most commonly within individuals of Askenazki Jewish ancestry. To our knowledge, no occurrence of c.4825C>A in individuals affected with Alport Syndrome and no experimental evidence demonstrating its impact on protein function have been reported. Four clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014. Three laboratories classified the variant as VUS and one classified it as benign. Based on the evidence outlined above, the variant was classified as likely benign.